Agronomics and Sustainability of Transgenic Cotton in Argentina

Abstract

Bt cotton was among the first transgenic crops to be used in commercial agriculture. A gene from the soil bacterium Bacillus thuringiensis (Bt) has been transferred to the cotton genome. This gene codes for production of a protein that is toxic to the cotton bollworm, a severe insect pest in most cotton-growing regions of the world. In the United States and China, Bt cotton was commercialized in the mid-1990s, and today, the technology covers around 30-40% of the cotton area in both countries. Recent studies demonstrate that US and Chinese Bt adopters realize significant pesticide and cost savings (Carpenter et al., 2002; Pray, Huang, Hu, & Rozelle, 2002). Benefits of Bt cotton have also been reported for South Africa (Shankar & Thirtle, 2003) and Mexico (Traxler, Godoy-Avila, Falck-Zepeda, & Espinoza-Arellan, 2001). Nonetheless, there is still uncertainty related to the technologyís impacts and sustainability under different agroecological and socioeconomic conditions. This article analyzes the implications of Bt cotton in Argentina, where the technology was commercialized by Monsanto in 1998. Unlike other Bt-growing countries, where cotton is a heavily subsidized crop, Argentina is producing under free-trade conditions, with comparatively low input intensities and production costs. This might influence the technologyís agronomic outcome. Apart from a comparative analysis of pesticide use and yields with and without Bt, productivity effects are modeled econometrically using a damage control specification. This analysis is based on a comprehensive survey of Argentine cotton farmers in 2001 done jointly with Argentinaís National Institute for Farming and Livestock Technology (INTA). Although short-run gains of the technology are increasingly recognized (Qaim & Zilberman, 2003), long-run effects associated with pest resistance remain in doubt. We address this issue by using biological models to simulate possible resistance development in bollworm populations. Although resistance buildup has not been observed in the field so far, biochemical studies indicate a high risk of rapid insect adaptation to the Bt toxin (Gould, 1998). Resistance development is one of the main concerns of environmentalists with respect to Bt crops. It would not only challenge the technologyís sustainability, but would also imply loss of Bt as an ecologically friendly microbial insecticide that is widely used in organic agriculture.